Route circuit network control apparatus for railway signals



E. M. ALLEN ROUTE CIRCUIT NETWORK CONTROL APPARATUS FOR RAILWAY SIGNALS Dec. 25, 1951 2 SHEETS-SHEET l Filed Jan. 17, 1947 'a'lf M Allen HIS A TTIZNEY Dec. 25, 1951 E. M. ALLEN ROUTE CIRCUIT NETWORK ,CONTROL APPARATUS FOR RAILWAY SIGNALS 2 SHEETS-SHEET 2 Filed Jan. 17, 194'? INVENToR Earl Alen HIS ATWIZNEY Patented Dec. 25, 1951 ROUTE CIRCUIT NETWORK CONTROL APPARATUS FOR RAILWAY SIGNALS Earl M. Allen, Chicago, Ill., assignor to Westinghouse Air Brake Company, a corporation of Pennsylvania Application January 17, 1947, Serial No. 722,520

8 Claims. (Cl. 246-3) My invention relates to remote controlling apparatus, and particularly to apparatus at an oice station for controlling apparatus at a field station for in turn controlling railway traiiic governing devices such, for example, as switches and signals.

In apparatus of this type, it is common practice to provide a route circuit network at an office station for controlling route relays which control signal relays at a eld station. The route circuit network includes contacts of switch levers and switch indication relays in addition to contacts of signal levers, according to the routes governed by the signals. Signal circuits at the eld station include contacts of the signal relays and also include contacts which are closed according to the position of the switches in the routes governed by the signals. A signal relay, upon becoming energized for clearing a signal, opens the circuits for a corresponding route locking relay at the iield station to prevent operation of the switches in the-corresponding route, and opens the circuits for opposing signals.

Stick locking relays provided in iield station apparatus are controlled in part by contacts of the signal relays. These stick locking relays are kcontrolled by the signal relays to be energized only while contacts of the signal relays in the signal circuits at the eld station are open for causing the associated signals to indicate stop.

If trafic conditions are such as to cause the signal circuit, at the field station, for any given signal to be open, the given signal will continue to indicate stop while the associated signal relay, if controlled according to prior practice, may be in condition for controlling the given signalV to display a proceed indication. Therefore an associated stick locking relay might become deenergized while the associated signal cannot be cleared.

One or more track switches in a route governed by a given signal are controlled in part by a iront contact of the stick locking relay which is asscciated with the given signal. Accordingly, the track switches cannot be operated if the stick. locking relay is deenergized.

It is sometimes desirable tok operate a track switch when a given signal which governs traiiic movements over the switch cannot be cleared. Furthermore, in the signaling arrangement shown. by applicant, an opposing signal is controlled in part by a front contact of a stick lockingrelay associated with the given signal. It follows that it is desirable to prevent operation of a signal relay for clearing a signal and deenergizing an as sociatedstick locking relay if traiiic conditions are such vthat the signal cannot be cleared although it is safe tooperate a track switch in a route governed by the signal.

One feature of my invention is thereiore the provision of means in the route circuit network to prevent energization of a route relay, and a corresponding signal relay, if an opposing signal has been cleared and if a train occupies the stretch of ,track between the opposing signal and the signal controlled by the route relay.

Another feature of my invention is the provision of means in the route circuit network for energizing a route relay to control its signal to display a call-on indication if a train has passed its signal and occupies a given portion of the stretch of track in advance of its signal.

Because of these features of applicants invention, energization of a route relay, and in turn, the energization of a signal relay which is controlled by the route relay, are prevented under certain conditions which prevent clearing of a .signal but which would permit operation of a track switch in a route governed by the signal.

In previous practice, the signal circuit in the 'lield apparatus was controlled to prevent clearing of a signal under those certain conditions but the route relay was free fromY such control, so that the signal relay could be energized for clearing the signal and deenergizing an associated stick locking relay. With applicants invention, there fore, a track switch is left free to be operated for preparing a different route at times when a given signal cannot be cleared for governing traffic movements over the switch. Also, with applicants invention, an opposing signal, in the signaling arrangement shown by applicant, cannot at times be unnecessarily caused to indicate stop.

I shall describe one form of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1a and 1b, when placed end to end, with Fig. 1a on the left, constitute a diagrammatic View showing one form of apparatus embodying my invention, in which a stretch of track is provided with switches and signals including a signal at each end of the stretch for governing traiiic movements in opposite directions into the stretch, together with apparatus at ield stations for controlling the switches and signals and for controlling repeater or indication relays at the ofilce station; and Fig. la shows the indication relays at the cnice station, together with apparatus for controlling apparatus at the eld stations.

In the form of apparatus shown in the accompanying drawings, the apparatus at the oiiice station is shown controlling the eld station apf February 17, 1942, to C. S. Snavely and A. B;

Miller for Remote Control Systems.

divided by insulated joints I yto form switch sec;4

tions designated by the reference characters 21T, 43T and SlT in which switches B21-B53 andB5l, respectively, are located, and block sections, designated by the reference characters 352T and RSI. Eachof these track sections isprovided with a track circuit including a suitable source of current such as abattery V2, connected across the rails adjacent one end of thesection, and a track relay, designated by a reference character which is the same as the reference character for its section except that it includes also the letter R, connected across the rails adjacent the opposite end of the section. As is obvious and well-known, such track relays are traflic responsive relays, being responsive to railway traffic movements over the corresponding track sections.

Traiiic movements toward the right, as shown in the drawings, which I shall assumeis the eastbounddirection, are `governed by a group of signals R55 mounted on 4a cornnionjmasabya signal 352, and by a group of signals R35 including a` signal RA30. Traic movements in the opposite, or westbound direction, are governed by signals L58 and L35'. yEhe signals maybe of any suitable design such, for example, as the semaphore or the searchlight 'typ-e.r

Switches A51 and B51 are operable to their normal positions, inwnich they are shown in the drawing, or to the opposite or reverse positions, by mechanisms designated by the reference chanacters AM and BM, respectively. Mechanisms AM and BMv are in turncontroiled by field equipment at a eld station through contacts of a switch locking relay in response to manipulation of a switch control lever 57V at thecontrol station. Operation of switches A2?A andB'E? may be controlled by a Alever ZlV, and operation of switches A43 and B43 may be similarly conn trol-led by alever "53V, as shown inlig. lla of the drawings.

A switch repeater relay 5'iNP is controlled in conjunction with switches A51 and B5l to be energized when both of these switches are in the normal position. Relay 21N? is similarly conm trolled in conjunction'withswitches A222' and B2i.

Signal L58 is controlled to display a clear or proceed indication by a circuit which includes a reverse polar contact 'H of av polar stick signal relay L5SHS anda front Contact 'i5 of vswitch repeater relay 55N?. Relay L58HS is controlled by equipment at the oce stationthrough energization of a route relay L5SGS. The circuit-for controlling signa-11458 also includes contacts'of a slow releasing traiilc relay LESFR and a directional stick relay L5SSR; Relay -LESSR becomes energized when a westbound train enters section 352T.

A normally energized stick locking relay LEBALS becomes deenergized when relay L5M-IS becomes energized in vthe reverse direction for clearing signal L58.

f A secondnormally lenergized stick locking relay RSBALS is controlled, in conjunction with sigassalto nais R58, similarly to the manner in which relay L53ALS is controlled in conjunction with signal L58.

A route locking relay MWSR becomes deenergized in response to de'energization of relay LESALS.

Switch locking relay E'ELR also becomes deenergized in response to the deenergization of relay L5SALS, and remains deenergized while a train is in section 51T, or while relay 51MSR is deenergized.

Operation of signal 352 to display a caution indication is controlled by relays 5lWSR and L58SR and also by track relay 352TR. Only the caution control circuit is shown for signal 352, but this signal could also be controlled to display a proceed indication by a circuit controlled by these relays, if signal R58 is controlled to display aproceed indication.

A block indication lrelay L58BR is controlled by contacts of relays 352TR and RSQTR Relays 5lNP, LiBRv and L5SSR controlindi'- cation relays EENWK, LESBK and L55SK, respectively, at the oirlce station,

Block indication relay L58BR, on account of being controlled by traffic responsive track relays, is obviously alsoatrac responsive relay, and indication relay L5BBK, on account of being controlled by relay L5SBR, is also obviously a traffic responsive relay.

A second directional stick relay 3525i?. is arranged Ato become energized when a train passes signal S52 into section 352T while vsignal 352 is displaying a caution or a proceed indication.

A slow releasing signal repeater relay 352PR is controlled in conjunction with signal to be energized if signal 352 is indicating caution or proceed.

A stop indication repeater relay L53RP is controlled in conjunction with signal L58 to be energized if and only if signalLES is indicating stop.

Operation of signal RAil to display a proceed indication is controlledby relay 352PR and by a second tralic relay RSFR, which is slow releas ing, and also by a signal lever 30V at the oiiice station.

A third directional stick relay R35SR is arranged to become energized when an eastbound train enters section R30 while relay RSUFR is energized.

Referring to Fig'. la, control apparatus is shown in an oflice or control station which may, ior example, be a dispatchers oiiioe, for manually controlling switches A51 and B57 and signal L58. Indication relays :"elNWK, LES BK and LESK are shown which Vare controlled by relays 5`iNP, L58BR and LEBSR, respectively. A normally energized route locking relay Z'EESR is also shown which is associated with signals R35 and which is arranged to become deenergized when signal RABO is manually controlled to display a proceed indication while lever 53V is in its n position, and which then remains deenergized while a train occupies section 21T or 43T.

Manually operable levers, designated by the reference characters 30V and 58V, are shown for controlling signals 35 and '58, respectively. Each of these levers has a normal or n position, in which the lever is shown in the drawing, and also has reverse positions f and r. Manually operable levers 27V, 43V and 57V are also shown for controlling op-eration of switches 2l, 53 and 5l, respectively. Each of these levers 'hasa normal position n, in which it-is shown in the drawing, and a reverse position r.Y

A route relay L58GS is shown controlled by circuits which may be part of a route control circuit network.

Having described, in general, the arrangement and control of the apparatus shown by the accompanying drawings, I shall now describe, in detail, its operation.

As shown by the drawings, all parts are in their normal condition, that is, all switches are in their normal position; all signals except signal 352 are indicating stop, and signal 352 is indicating caution; all track sections are unoccupied, and hence the track relays are energized; each of the levers shown in Fig. la is in its n position; contacts of relay 1158HS are in their normal position; relays 'lNP, 57WSR, L58BR, L5BALS, RESALE), L5SRP, B'ILR, SEEPR, LEQBR, HNP, RSBFR, ETNWK, L58BR and NES-R are energized; and relays L58BR, 352SR, R35SR, L and L58GS are deenergized.

The circuit by which relay 51N? is energized passes from terminal B of a suitable source of current, such for example as a battery Q shown in Fig. 1b of the drawings, through contact 3 closed when switch A51 is in the normal position, contact 4 closed when switch B57 is in its normal position, and the winding of relay 5'lNP to terminal N of the same source of current.

Relay 5'IWSR is energized by both a pick-up and a stick circuit, the pick-up circuit passing from terminal B, through contacts l and 8 of relays L58ALS and 5'iTR, respectively, and the winding of relay 57WSR to terminal N. The stick circuit is the same as the pick-up circuit just traced for this relay except that it includes contact 9 of relay 5'IWSR instead of contact 5 of relay 5'ITR.

Signal 352 is controlled to display the caution indication by a circuit passing from terminal B. through contact I 0 of relay 5'lWSR, contact I i of relay L58SR, contact i2 of relay 352TR, and the mechanism of signal 352 to terminal N. Relay 352PR is energized by an obvious circuit which includes a contact I3 closed by signal 352 while this signal is indicating caution or proceed.

Relay L58FR is energized by a circuit passing from terminal B, through contacts I4, Il, I8 and I 9 of relays ZYIESR, RSQSR, L58BR, and 352SR, respectively, and the winding of relay L58FR to terminal N.

Relay L58RP is energized by an obvious circuit which includes a contact 82 closed in conjunction with signal L58 while this signal is indicating stop.

` Relay L58ALS is energized by a stick circuitpassing from terminal B, through contact 20 of relay L58HS closed in the normal or left-hand position, contact 2| of relay LESSRP, the front point of contact 24 of relay L53ALS, and the winding of relay L58ALS to terminal N. f

Relay 51LR is energized by a circuit which includes vcontact 25 of relay LSSALS, contacts 25, 2S, and 29 of relays R5BALS, 5TTR, and 5'lWSR, respectively, and the winding of relay 51LR to terminal N.

Relay L58BR is energized by a circuit passing from terminal B, through contact 3i of relay 352TR, contact 32 of relay R35TR, and the wind-A ing of relay L58BR to terminal N.

Relay R39FR is energized by a circuit passing from terminal B, through the front point of contact 34 of relay 352PR, contact 35 of relay RBBTR, and the winding of relay'RBFRfto terminal N.

Both a pick-up and a'stick circuit are -closed for energizing relay 2IESR shown in Fig. 1a.

-assalto 6 The pick-up circuit passes from terminal B, through contact 36 of lever 30V closed in the n or the f position or at any point between the n and the f positions, contacts 38 and 39 of relays 2'ITR and 43TR, respectively, and the winding of relay 2'IESR to terminal N. The stick circuit is the same as the pick-up circuit just traced except that it includes contact of relay 21ESR instead of contacts 38 and 39 of relays Z'ITR and' I shall assume that a leverman or dispatcher moves lever 35V to its r position for controlling signal RA30 to display a` proceed indication. Lever 30V, upon being moved to its r position, opens its contact 36, thereby deenergizing relay 21ESR. With lever 35V in its r position, the arm of signal RA30 is operated to display the proceed indication by a circuit passing from terminal B, through contacts 54, A35, 46, and 41 of relays 352PR, RSGFR, ZTTR, and 53TR, respectively, contact 48 of lever 35V, and the mechanism of signal RAS to terminal N.

When an eastbound train passes signal RA30 and enters section 43T. deenergizing relay 43TR, contact 41 of relay 43TR opens the circuit traced for signal RA30, causing this signal to again display the stop indication. If, now, the dispatcher returns lever 35V to its n position, closing contact 35 of lever 313V, relay ZlESR will still not become energized because its pick-up circuit is open at contact 39 of relay 43TH. Since the pick-up circuit for relay ZIESR also includes contact 38 of relay Z'ITR, relay Z'IESR will remain deenergized as long as the train occupies either section 21T or 43T.

I shall assume also, that while relay ZIESR is deenergized either because lever 35V is in its r position or because a train is in section 21T or 43T, the dispatcher attempts to clear signal L58 for a westbound train by moving lever 58V to its Af position. On account of relay ZlESR being de- 7 moved to the f position, relay LEBGS cannot be:

come energized. With relay L58GS deenergized, relay L58HS cannot become energized in the reverse direction although lever 58V is moved to the f position, since contact 83 of relay L58GS is now open. The contacts of relay L58HS will therefore remain in the normal position, and hence signal L58 canot be cleared. A

If the circuits for relay L58GS did not include contact 63 of relay ZTESR, so that relay L58GS could now become energized, relay L58HS would become energized in the reverse direction by a circuit controlled by contact l0 of lever 53V closed in the f position, and contact 83 of relay L58GS. Relay L5M-IS, upon thus becoming energized in the reverse direction, would open its contact 25 in the stick circuit previously traced for relay L58ALS, causing this relay to become deenergized. Relay L53ALS, upon becoming deenergized, would open its contact 'I in the circuit previously traced for relay 51WSR, causing relay 57WSR to become deenergized. With relay 5'IWRS deenergized, its contact Hl would open the circuit previously traced for signal 352, causing signal 352 to display a stop indication while a train is approaching signal 352 after having passed signal RASU. 'K

When a train enters section R351?, contact 32 of relay RSiiTR opens the circuit previously Ytraced for relay LiiiiBR, and hence contact'l of relay L58BR opens the control circuit for relay LSBBK, causing relaywLBBBK to become deenergized.

'Deenergization ofrelay'R38T-R closes a pickl up circuit `for relay ',RSR, passing from. terminalB, through contact it of relayfRSilTR, front point of ccntact .of relay VR30li1.,fcontact 5l of relay Z'ZTR, `andthe vvindinglo'f relayRSUSR to terminal N. Although contact 35 of relay RS BTR opens the circuit previously traced for relay RSQFR, causing relay RSGFR to becomedeenergized, this relay is of the slow releasing type, and hence its contact i] remains closed at the front point lOng enough for relay RSESR .to rbecome energized. When contact 58 of Y. relay RtElFR becomes closed at its back point, .a stick circuit is closed forrelayRQSRrpassing from terminal B, through theback point of ,contact58 of relay'RSilFR, contact 52 of relay lEtIillSlx `and 'une vinding of relay Riesa te terminn N.'

With relay R3QSRenergized, its contact |71 in the circuit previously traced for relayLSiFRnoW becomes opened in addition ,to contact llol relay MESH..

With relay L BK deenergized, Contact ,5.8. of this relay will be openinthe circuit for relay LEBGS in addition to contact. 53 of relay N ESR, and hence relay LGS Will remaindeenergized as long 4as'the Veastbound ,train .causes .relay L5BK to remain deenergizefd. luthis way, the dispatcher is ,prevented from effecting energizaticnof relayLiiHS in thereverse position which would cause Asignal .352 vvto .change .to the stop indication while an, eastbound...train ,is approaching this signal.

.When an eastbound train passessignal $52, causing relay 352TR to become deenergized, con tactlvof relay VCJVEZTR opensthe circuit previously tracedfor signal 3,52, causing this signal to display the stop indication. Contact i3 of signal 352 will. thereupon open theicircuitfor re- 'l lay 352PR, causingr this relay to becomedeenergized.

sections 352T and 51T, all parts of the apparatus will again be in the normal condition.

I shalll now assume that, with all parts of the apparatus again in the normal condition, the dispatcher decides to clear signal L58 fora westbound train. He will, therefore, move lever 58V to its f position. Relay LSBGS will then become energized by a circuit passing from terminal B, through contact 53 of relay Z'IESR, contact65 oi lever 51V, contact 66 of lever 58V closed in the f position, contacts 61 and 58 of relays 51NWK and L58BK, respectively, and the winding'of relay L58GS to terminal N. With lever 58V in its f position, its contact l0 will be closed in a circuit which includes contact 83 of relay LEBGS for effecting energization ,ofv relay L58HS in the reverse direction.

Relay L5M-IS, upon thus vbecoming:energized in the reverse direction, opens its contact 28 in the circuit previously traced for relay L58ALS, causing this relay to become deenergized. .Relay L58ALS, upon becoming deenergized, opens its contact `25 in the circuit previously described for relay lLR, causing this relay to .become deenergized and open its contacts V5 and 5 in the circuits for operating mechanisms AM and BM for switches A51 and B51, respectively. vRelay L'iiiALS, upon-becoming deenergized, also opens its contact 'i in the circuits previously traced for relay E'IWSR, causing this relay tcalso become deenergized. Contact 29 of relay''lWSR will now also be opened in the circuit'previously traced for relay 5`l`LR.. Relay EIWSR, upon becomingdeenergized, Willopen itscontact l0 in the circuit previously traced for signal.fl2,'caus n ing `thissignalto display'the stopindication.

Relay 352153, upon rbecoming .deenergized,

this circuit passing from terminal B, through the haci: point of contactlliof relay `.'iiiPlEt, contact of rel-ay SEBSR, .andthe winding .of relay SEZSR to terminal N. I-ViFith relay 35251?, energized, contact i ii ofv this relay will rbe open in the circuit traced for relay LSBFR.

When the train leaves-section RMT; relay RS'BFR will become energized'by a circuit passing rom"terminal B, through contact A33 of 'relay 352SR,*back point of contact'34 or" relay "352PR,"

contact 35 ofrelay'RSilTR, and the winding of relayfR'SlR to terminal N. When relayRB'ifB, beccmesenergized, its contact i9 will open theiirst stiel: circuit previously traced for relay RSQSR, and whenrelay RSGFR becomes energized, the second stick circuit for relay `R-PilSl. will become opened at the back point of Contact 58 ofrelay RSEFR, causing V.relay REQSR to .again become de energized.

When .theeastbound train -has passed ,through With relay L58HS now energized in the reverse direction, and with relays L ALS 'and 5'ILR deenergizeda circuit is .completed for controlling signal L58 to display a yproceed indication, this circuit `passing from terminal YB, throughcontacts "H and 'l2 o f relays LSSI-IS and 5'lLR, respectively, front point of contact 'I3 `of relay LBBFR, contacts l5, T6, 'Vl and "a8 lof relays 5'INP, SiTR, R58ALS and L58ALS, respectively, and the mechanism of signal L58 to terminal N.

If now the dispatcher decides to control signal L58 to again display the stop indication before the arrival of a westbound train, he will return lever 58V to its n position, causing relay lLtlHS to again become energized by its Vnormal,control circuit which includes contact 1i! of lever 58V in the n position. Contact H of relay LEBHS Will therefore lopen the circuit previously traced for signal L58, causing signal L58 to indicate stop. With signal L58 again indicating stop, relay LSSRP will again become energized by its circuit previously described. A circuit is thus coinpletcd for energizing a time lelement device L58TE which may be of any suitable design, such for example as the well-known thermal type. This circuit for energizing device L58TE passes from terminal lB, through contacts 25 and 2l of relays L58I-IS and L58RP, respectively, back point of contact 24 of relay L58ALS, and time element device L58TE, to terminalN. vUpon the lapse of a measured period of time, device LSTE will close its contact 23, thereby completing a pickup circuit for energizing relay LSBALS. 'Ivhis pickup circuit passes from terminal `B, through contacts 20 .and 2l of relays LSSI-IS and L58RP, respectively, contact23 of device L58TEV, and the Winding of relay L58ALS, Yto terminal N. 1Relay LBSALS, ,upon thus vbecoming energized, opens its' contact 24 at the back point, thcrebyQ/deenergzassenso ing device L58TE, and closes this contact 24 at the front point, therebyl again completing the stick circuit previously traced for relay L58ALS.

If the dispatcher now again clears signal L58, then when a Westbound train enters section 51T, contact 16 of relay 57TH. will open the circuit traced for signal L58, causing this signal to return to the stop indication. Contact 23 of relay S'ITR will also be open in the circuit traced for relay E'ILR. If the dispatcher noW returns lever 58V to its n position so that relay L58HS again becomes energized in the normal direction, relay L58ALS will become energized by a second pickup circuit passing from terminal B, through contact 20 of relay L58I-IS, contacts 2l and 22 of relays L58RP and 51TR, respectively, and the Winding of relay L58ALS to terminal N.

When the westbound train enters section 352T, relay L58SR will become energized by a pick-up circuit passing from terminal B, through contact 19 of relay 352TR, front point of contact 85 of relay L58FR, and the Winding of relay L58SR to terminal N. Relay LSSR, upon becoming energized, completes its stick circuit passing from terminal B, through contact I9 of relay 352TR, contact 8l of relay L58SR, and the winding of relay L58SR to terminal N. Relay L58BR will become deenergized on account of contact 3! of relay 352TR becoming opened. Relay LSSBR will then open its contact I8, causing relay L5BFR to become deenergized and complete a second stick circuit for relay L58SR passing from terminal B, through the back point of contact 88 of relay LESFR, contact 8l of relay L58SR, and the winding of relay L58SR to terminal N. Relay L58SR, upon becoming energized, completes a circuit including its contact 62 for effecting energization of relay L53SK.

When the train leaves section 57T, the dispatcher can then clear signal 58 for a call-on traiiic movement by effecting energization of relay L58GS by a circuit which is the same as the circuit previously traced for relay L58GS eX- cept that it includes contact 69 of relay LEBSK instead of contact 68 of relay L58BK. Relay L58GS, upon becoming energized, effects energization of relay L58HS in the reverse direction, f

so that a second circuit for clearing signal L58 is novvy completed which is the same as the circuit previously traced for signal L58 except that it includes a back point of contact 'I3 of relay LSSFR and contact i4 of relay LSBSR instead of the front point of contact 13 of relay LESER.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modications may be made therein Within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, What I claim is:

1. In combination, a stretch of railway track, a first and a second signal located at opposite ends of said stretch for governing traic movements into said stretch in opposite directions, a normally energized route locking relay associated with said first signal, manually controllable means for controlling said first signal and for deenergizing said route locking relay when said first signal is manually controlled to display a proceed indication, traffic responsive means for 'then retaining said route locking relay deenergized while a train occupies a portion of said r4stretch oi track in advance of said rst signal, a

trafc responsive relay, normally energized means for energizing said traiiic responsive relay but becoming deenergized when a train occupies a second portion of said stretch of track, a directional stick relay, a pick-up circuit for energizing said stick relay when a train moving in the direction in which it is governed by said second signal enters said second portion of said stretch, a stick circuit for then retaining said stick relay energized while said train occupies said second portion of said stretch, and a control circuit for said second signal controlled by a front contact of said route locking relay and also controlled by a front contact of said traflic responsive relay in multiple with means controlled by a front contact of said directional stick relay,

2. In combination, a stretch of railway track, a firstl and a second signal located at opposite ends of said stretch for governing traic movements into said stretch in opposite directions, a normally energized route locking relay associated with said rst signal, manually controllable means for controlling said rst signal and for deenergizing said route locking relay when said first signal is manually controlled to display a proceed indication, traffic responsive means for then retaining said route locking relay deenergized while a. train occupies a portion oik said stretch of track in advance of said first signal, a traic responsive relay, normally energized means for energizing said tralic responsive relay but becoming deenergized when a train occupies a second portion of said stretch of track, a directional relay, means for energizing said directional relay when a train moving in the direction in which it is governed `by said second signal enters i said stretch, and a control circuit for said second signal controlled by a front contact of said route llocking relay and controlled by a front contact of said trac responsive relay in multiple with means controlled by va front contact of said directional relay and also controlled by manually controllable means for clearing said second signal and preventing clearing of said rst signal.

' 3.. In combination, a stretch of railway track, a rst and a second signal locatedat opposite ends of said stretch for governing traiiic movements into said stretch in opposite directions, a normally energized route locking relay associated Withsaid first signal, manually controllable means for controlling said first signal andV for deenergizing said route locking relay When said first signal is manually controlled to display a proceed indication, trafc responsive means for then retaining said route locking relay deenergized While a train occupies a portion of said stretch of track in advance of said first signal, a traii'ic responsive relay, normally energized means for` energizingsaid traiic responsive relay but becoming deenergized when a train occupies a second portion of said stretch of track, a directional relay, means for energizing said directional relay when a train moving in the direction in whichit is governed by said second signal enters Asaid second portion ofvsaid stretch, means for then retaining said directional relay energized While said train occupies said second portion of said stretch, manually controllable means controlledalso by -said route locking relay and by said traiiic responsive relay for clearing said second signal if said rst sgnalis indicating stop and if rsaid stretchof track is unoccupied, and

manually controllable means controlled also by vsaid directional relay for clearing said second signal for a call-on traffic movement if said stretch of track is occupied by a train moving from said second signal toward said rst signal.

4. In a remote control system comprising an oice station and a eld station for controlling a plurality of railway traffic governing devices including a first anda second signal at opposite ends of a given stretch of track for governing traiiic movements into said stretch in opposite directions, the combination comprising, a normally energized route locking relay associated With said first signal, manually controllable means for deenergizing said route locking relay when said rst signal is controlled to display a proceed indication, train controlled means for thenretaining said route locking relay deenergized while a train occupies a portion of said stretch, a portion of a route network' at said office station including a control circuit for said second signal controlled by a front contact of said route locking relay and by a manually operlable device, a locking relay at said eld station, a polar stick relay controlled by said control circuit at said oice station for clearing said second signal and deenergizing said locking relay at said field station, and control means for said rst signal including a front contact of said locking relay at said eld station.

5.. In a remote control system comprising an oiiice station and a eld station for controlling a plurality of railway traffic governing devices including a first and a second signal at opposite ends of a given stretch of track for governing traffic movements into said stretch in opposite directions, the combination comprising, a manually operable device for controlling said iirst signal, a normally closed contact controlled by said manually operable device which becomes opened if said rst signal is controlled by said manually operable device to display a proceed indication, traffic responsive means, a second normally closed contact controlled by said traflic responsive means which becomes opened if a train occupies 'a portion of said stretch, a control circuit at said ofce station for said second signal controlled by said first and second contacts and by a second manually operable device, al locking relay at said field station, means controlled by said control circuit at said office station for `clearing said second signal and deenerg'izing said locking relay, and control means for said rst signal including a front contact of said locking relay,

6. In a remote control system comprising an oice' station and a eld station for controlling a plurality of railway traffic governing devices including a first and a second signal at opposite endsV of a given stretch of track for governing trailic movements' into said stretch in opposite directions, the combination comprising, a manually operable device for controlling said first signal, a normally closed contact controlled by said manually operable device which becomes opened if said first signal is controlled by said manually operable device to display a proceed indication, traic responsive means, a second normally closed contact controlled by said traiiic responsive means which becomes opened if a sponsive means whichl becomes closed if a train passes said second signal into said stretch', a co'ntrol circuit at said oce station including said rst contact and including said second contact in multiple with said third contact and also including a manually controllable contact, a locking relay at said eld station, means controlled by said control circuit at Vsaid oice station for clearing said second signal and deenergizing said locking relay, and control means for said first signal including a front contact of said locking relay.

7. In a remote control systemY comprising an oiiice station and a eld station for controlling a plurality of railway traiic governing devices including a rst and a second signal at Opposite ends of a given stretch of track for governing trac movements into said stretch in opposite directions, the combination comprising, a manually operable device for controlling said rst signal, a normally closed contact controlled by said manually operable device which becomes opened if said rst signal is controlled by said manually operable device to display a proceed indication, trame responsive means, a second normally closed contact controlled by said trac responsive means which becomes opened if a g circuit at said oiiice station for said second signal 1 controlled by said first and second contacts and by a second manually operable device, a locking relay at said field station, means controlled by said control circuit at said oce station for clearing said second signal and deenergizing said locking relay, a track switch in a route governed by said second signal, and control means for said track switch including a front contact of said locking relay.

8. In a remote control system comprising an cnice station and a eld station for controlling a plurality of railway traffic governing devices including a first anda second signal at opposite ends of a given stretch of track for governing traffic movementsinto said stretch in opposite directions, the combination comprising, a normally energized route locking relay associated with said iirst' signal, manually controllable means for deenergizing said route locking relay when said first signal is controlled to display a proceed indication, train controlled means for then retaining said route locking relay d eenergized while a train occupies a portionA of said stretch, a route network at said oiiice station including a control circuit for said second signal controlled by a front contact of said route locking relay and by a manually operable device, a locking relay at said eld station, a polar stick relay controlled by said control circuit at said oflice station for clearing said second signal and deenergizing said locking relay at said field sta!- tion, and control means for a track switch in va route governed by said second signal including a front contact of said locking relay.

EARL M. ALLEN.

CITED The following references are of recordl in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,109,153 Phinney Feb. 22, 1938 2,317,732 Coleyv Y Apr. 27, 1943 2,342,488 Preston Feb. 22, 1944 

